In modern communication systems, connections such as for voice, video or multimedia communication are increasingly being carried over packet-based communication networks, such as local area networks (LAN) or wide area networks (WAN) So-called Internet telephony, for example, often also referred to as “Voice over Internet Protocol” (VoIP), is based on this technology.
In such packet-based communication networks, the user data to be transmitted is split into individual data packets which are provided with a transport address that identifies the respective connection destination. On the basis of the transport address the data packets are forwarded in the communication network to the respective connection destination independently of each other to a large extent.
A central connection controller is often employed in packet-based communication networks. As a rule, such a connection controller manages the establishment and clearing of connections, ensures a defined quality of service for establishment connections, protects against unauthorized use, and enables the use of features such as call forwarding or proxy functionality, for example.
Known from ITU-T Recommendation H.323 is a packet-based communication network in which a so-called gatekeeper is used as a connection controller for controlling and managing all real-time multimedia connections within the communication network or a subnetwork of the communication network. According to the prior at, in order to establish a connection from a first communication network managed by a first gatekeeper in a second communication system managed by a second gatekeeper, signaling is required between the first and the second gatekeeper. However, such signaling between different gatekeepers requires a high implementation effort, especially if there are also one or more further packet-based communication networks between the first and second communication networks. Typical examples of such an arrangement are local area networks located at various company offices which are linked together via the Internet.
Another disadvantage of the known gatekeeper-controlled communication network is that from the first communication network it is only possible to establish connections to communication networks also managed by a gatekeeper. The choice of connection destination is thus greatly limited.
An object of the present invention is, therefore, to disclose a method for establishing a connection from a network-internal terminal of a packet-based communication network having a network-internal connection controller to a network-external connection destination for which no complex signaling is required between the network-internal and a network-external connection controller. It is also an object of the present invention to disclose a packet-based communication network and a gateway device for achieving the method according to the present invention.